<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <link rel="stylesheet" href="./main.css">
  <style>
    .ca {
      color: red;
    }

    .foo {
      font-size: 50px;
      color: blue;
    }
  </style>
</head>

<body>
  <h2 class="ca cb ce">title2</h2>
  <div>box1</div>
  <p class="cat pig">hello p1</p>
  <h2 class="rabit foo">title2</h2>
  <div class="rabit ca">box2</div>
  <p>hello p2</p>
  <h2>title3</h2>
  <div class="foo ce">box3</div>
</body>

</html>